package cn.edu.gxust.blogex.gateway.utils;


import org.springframework.http.HttpHeaders;
import org.springframework.http.server.reactive.ServerHttpRequest;

import java.net.InetSocketAddress;

/**
 * @author zhaoyijie
 * @since 2022/3/18 23:29
 */
public class NetworkUtils {

    public static String getIPAddress(ServerHttpRequest request) {
        String ip = null;
        HttpHeaders httpHeaders = request.getHeaders();
        //X-Forwarded-For：Squid 服务代理
        String ipAddresses = httpHeaders.getFirst("X-Forwarded-For");

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //Proxy-Client-IP：apache 服务代理
            ipAddresses = httpHeaders.getFirst("Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //WL-Proxy-Client-IP：weblogic 服务代理
            ipAddresses = httpHeaders.getFirst("WL-Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //HTTP_CLIENT_IP：有些代理服务器
            ipAddresses = httpHeaders.getFirst("HTTP_CLIENT_IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //X-Real-IP：nginx服务代理
            ipAddresses = httpHeaders.getFirst("X-Real-IP");
        }

        //有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
        if (ipAddresses != null && ipAddresses.length() != 0) {
            ip = ipAddresses.split(",")[0];
        }

        //还是不能获取到，最后再通过request.getRemoteAddress().getHostName();获取
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            InetSocketAddress remoteAddress = request.getRemoteAddress();
            if (null != remoteAddress) {
                ip = remoteAddress.getHostName();
            }
        }
        return ip;
    }

}
